| 摘要 |
PROBLEM TO BE SOLVED: To provide a refining method with which the reaction speed is increased at a low cost in a ladle refining of molten steel including deoxidation, desulfurization, de-nonmetallic inclusion, degassing and reduction. SOLUTION: Downward or upward spiral stream is introduced by setting a spiral rotating magnetic field generating apparatus on the same axis 14 as the center axis of the cylindrical ladle 11 to form circulating streams 7, 7' in the whole vessel, in which the core part and the outer peripheral part are made to flow in vertically reverse direction. Intense bubble-containing tornado streams 20 accelerating the circulating stream, are formed in the core part by applying the downward spiral stream in the gas bubbling under reducing pressure. Non-reacting molten steel at the lower zone is effectively shifted to a reaction range composed of four phases of gas-slag-molten steel-pseudo vacuum at the upper zone, and the improvement in refining speed and the enlargement of refining range are attained. COPYRIGHT: (C)2003,JPO
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